Yin is the third of the Twelve Earthly Branches, belonging to Yang Wood, associated with the Tiger zodiac sign, and corresponding to the Yin Hour (03:00–05:00). Yin Wood represents early-spring wood—internally containing Jia Wood, Bing Fire, and Wu Earth—characterized by vigorous growth and commanding strength, symbolizing pioneering spirit, initiative, and authoritative power. Yin Wood is the ‘Lu’ position of Jia Wood, embodying abundant vitality and flourishing energy.
Yin Wood is identified from the Earthly Branches in the Four Pillars of Destiny chart. If Yin appears in the Year Branch, the native belongs to the Tiger zodiac; if Yin appears in the Day Branch, the Spouse Palace is Yin Wood. Yin Wood is strongest during the Yin Month (first lunar month), when it is in season.
A person born on a Jia-Yin Day has Yin Wood as Friend in the Day Branch, suggesting a spouse with strong, resolute character who shares similar aspirations and values.